In case you guys didn't read the Back to Beta post, everyone who doesn't already have them actually gets a rental KV-220-2 and M4A2E4 Sherman. At the very least, everyone can join the random draw. They just need to pick a team.

so we get a 1 day rental but the event lasts for a week meaning to have any chance of getting the 500 and 400 gold prize u would have to almost play no stop for that 24 hr, players who buy the tanks get a week to get all the Fire For Effect achievements yep seems fair to me....

and players who buy the tank get 12k gold all ready what will they care about 500 more...

so we get a 1 day rental but the event lasts for a week meaning to have any chance of getting the 500 and 400 gold prize u would have to almost play no stop for that 24 hr, players who buy the tanks get a week to get all the Fire For Effect achievements yep seems fair to me....

and players who buy the tank get 12k gold all ready what will they care about 500 more...

The random draw event is so that everyone gets to participate. The top 20 for each tank also caters to people who have gotten the tanks in the past, not just the ones who buy them now. It's also dependent on whether or not they're in the winning team and if they managed to earn enough achievements.

I actually expect most to go for the 20 Fire for Effect achievements and just hope they get lucky.